Suction cups have long been used to grasp glass, tiles and windshields. A brief summary of the know art follows below.
U.S. Pat. No. 7,066,434 (2006) to Kwok discloses a suction cup with a rubber suction member covered by a plastic body. A neck extends up from the body. Inside the neck travels a stem which is attached to the rubber suction member. In the neutral position a spring in the neck biases the rubber suction member up (col. 2 line 61). To create a suction a button over the neck is depressed or a handle is pulled up. These actions push the rubber member away from the body. This is opposite to the Mayhugh invention. When the button is pushed down a red ring is covered by the neck. When the vacuum leaks, then the rubber member moves up, pushing up the button and exposing its red alarm ring. This invention does not provide a double action vacuum action with its handle. Also, the ring is physically depressed, depressed via a vacuum as in the Mayhugh invention.
U.S. Pat. No. 3,240,525 (1966) to Wood discloses a hand/finger pump on a suction cup. A red ring is located on the pump plunger. As the vacuum under the rubber member increases, the red ring disappears into the pump housing. When the vacuum leaks a spring pushes the plunger out creating a warning with the red ring exposed. No double action vacuum mechanism is shown, only the pump.
U.S. Pat. No. 7,004,521 (2006) to Ishii discloses a suction cup that has a locking handle to raise the rubber member via a rod imbedded in the rubber member. This theory is the same as Mayhugh's. No warning device is shown.
U.S. Pat. No. 5,795,001 (1998) to Burke discloses a suction cup which is activated by a battery operated vacuum pump with electronic alarm for vacuum loss.
U.S. Pat. No. 5,184,858 (1993) to Arai discloses a finger pump with an indicator red ring on the plunger. A battery operated sound alarm is also provided.
U.S. Pat. No. 7,293,750 (2007) to Richter discloses a lever operated suction member with a heat separating element.
U.S. Pat. No. 7,338,020 (2008) discloses a suction member that is pulled from the work surface like the Mayhugh invention. No indicator is shown.
U.S. Pat. No. 5,639,134 (1997) to Rusch et al. discloses the Auto Glass Specialists which has a finger pump. No indicator is shown.
U.S. Pat. No. 5,772,823 (1998) to Rusch et al. (Auto Glass Specialists) discloses a method to install a windshield using a suction cup with a sealant.
U.S. Pat. No. 6,039,371 (2000) to Smith discloses a flooring installation suction device.
U.S. Pat. No. 2,303,393 (1940) to Schmidt discloses a basic lever operated rubber member that is pushed against the glass for creation of a vacuum.
U.S. Pat. No. 2,370,938 (1945) to Cohen discloses a basic glass lifter suction cup which raises the rubber member like Mayhugh's invention. No indicator is shown.
U.S. Pat. No. 2,420,811 (1947) to Brewster et al. discloses a glass lifter suction cup which raises the rubber member like Mayhugh's invention. No indicator is shown.
U.S. Pat. No. 2,871,054 (1956) to Zinke discloses the same raise the rubber suction cup with no indicator like Brewster.
GB 2215058 discloses a low pressure indicator with a sliding rod moved by a pressure sensing diaphragm.
GB 954315 discloses a pump type suction cup with a leveraged handle for pumping.
U.S. Pat. No. 6,607,054 (2003) to Lindfield discloses a powered vacuum pump used to activate a suction cup.
U.S. Pat. No. 3,180,604 (1965) to Hammer discloses a pair of joined suction cups with a handle between them that can activate the cups.
U.S. Pat. No. 4,262,890 (1981) to Sisko et al. discloses an upside down suction cup for a ski holder.
U.S. Pat. No. 4,397,491 (1983) to Anderson discloses a hand pump suction cup.
U.S. Pat. No. 4,583,343 (1986) to Camp discloses a simple suction cup based tile setter. It is pump activated.
U.S. Pat. No. 4,597,727 (1986) to Birkhauser, III discloses a hand pump activated suction cup.
U.S. Pat. No. 5,395,159 (1995) to Pinto discloses a suction cup holding a headrest.
U.S. Pat. No. 5,909,758 (1999) to Kitamura discloses a hand rest on suction cups of the raise the diaphragm type.
U.S. Pat. No. 6,328,863 (2001) to Larsen discloses a suction cup for light weight CD's.
U.S. Pat. No. 6,609,689 (2003) to Knapp discloses a wall mount suction cup.
U.S. Pat. No. 6,913,232 (2005) to Richter discloses a raise diaphragm wall mount suction disc.
U.S. Pat. No. 7,021,593 (2006) to Fan discloses a suction disc rack.
Pub. No. US 2004/007888 discloses a raise diaphragm suction cup with a handle and release tab.
Pub. No. US 2007.0210225 discloses having an axial (twisting) suction cup.
What is needed in the art is a powerful suction cup for lifting windshields as is shown by Rusch et al '134. Additionally, the warning ring concept taught by Kwok '434 is needed. Finally, a quick to use handle is needed as a vacuum applicator to obtain the adherence to glass taught by Cohn '938, but achieve the great tenacity quickly without having to twist a knob.
The present invention meets all the needs, thus increasing the efficiency of a professional windshield installer.